These days, many of light-emitting elements that are used for displays and the like have a structure in which a layer including a luminescent material is interposed between a pair of electrodes. In the case of such a light-emitting element, light is emitted when an exciton formed by recombination of an electron injected from one electrode and a hole injected from the other returns to the ground state.
In the field of light-emitting elements, various studies have been conducted in order to obtain a light-emitting element that has favorable characteristics such as a high luminous efficiency.
For example, in Patent Reference 1, an organic electroluminescent element using a phenanthroline derivative is disclosed. In the element described in Patent Document 1, the phenanthroline derivative is used for an electron transporting layer.
However, in the case of the element described in Patent Document 1, while favorable characteristics can be obtained when an Mg—Ag alloy is used for an electrode as in embodiments, there is a possibility that electrons are not well injected into an electron transporting layer to make the driving voltage larger when an electrode composed of aluminum is used.
(Patent Reference 1) Japanese Patent Application Laid-Open No. 5-331459